Improvement in millstone-dressing machines



1. DAVIS Mill-Stone Dressing Machines.

N0.15l,655. Patentedlune2,1874.

WITNESSES. v INVENJOR A ttorneys UNITED STATES PATENT OFFICE.

JOEL DAVIS, OF DANVILLE, KENTUCKY.

IMPROVEMENT IN MILLSTONE-DRESSING MACHINES.

Specification forming part of Letters Patent No. 1 51,655, dated June 2,1874; application filed April 4, 1874.

To all whom it may concern:

Be it known that I, JOEL DAVIS, of Danville, in the county of Boyle andin the State of Kentucky, have invented certain new and usefulImprovements in Machines for Dressing Millstones; and do hereby declarethat the following is a full, clear, and exact de 'scription thereof,reference being had to the accompanying drawings, and to the letters ofreference marked thereon, making a part of this specification.

The nature of my invention consists in the construction and arrangementof a machine for dressing millstones, as will be hereinafter more fullyset forth.

In order to enable others skilled in the art to which my inventionappertains to make and use the same, I will now proceed to describe itsconstruction and operation, referring to the annexed drawing, in whichthe figure of the accompanying drawings is a perspective view.

A represents a rectangular frame of any suitable dimensions, in thesides of which slides a smaller frame, B. The sides of the frame B aregrooved longitudinally on the inside, and in said grooves are insertedtongues or ribs or a, formed on the sides of a head or carriage,

- O, the body of which fits between the sides of the frame B. The heador carriage O is made in two parts, as shown, hinged together at oneend, and fastened at the other end by screws passing up from underneath,and the heads of which enter countersinks in the bottom of the head.Through the head 0 is a vertical hole for the passage of a stem, D,which is fastened by means of a set-screw, b, and has a diamond pointattached in its lower end. This device is intended to make fine lines onthe millstone, which is accomplished by moving the head 0 back and forthin the frameB by means of a handle, E, attached thereto. The diamond isadjusted as desired, and held by means of the set-screw b. The frame Bis, at each end, provided with a projecting rackbar, j, which gears witha pinion or cog-wheel,

0, upon a shaft, G, having its bearings in suitable boxes upon the endpieces of the main frame A. Upon one end of the shaft G, outside of theframe A, is attached a springcrank, provided on its inner side, at theouter end, with a pin to enter recesses, depressions, or holes formed ina segmental bar, I, attached on theoutside of the frame A. The holes ordepressions in the bar I are made at regular intervals, so as to holdthe frame B at the desired points and regulate the width of thedistances between the lines to be out. On the center of the shaft G issecured a pulley, J, and to this pulley is fastened one end of a rubberband or spring, h, which is wrapped around the pulley, and the other endfastened to the frame B. The object of this spring is to take up theloose motion of the cog-gearing.

In operating and adjusting the frame B by means of the cog-gearing, asdescribed, there will invariably be some play laterally of the frame,and this will result in wabbling or wavy lines or grooves in the stone;but by the use of the rubberband this play or loose motion is taken up,and the frame held rigidly, so that the cutter can produceperfectlystraight grooves in the face of the millstone.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

In combination with the shaft G, its cogwheels 6 e on the main frame,and the rackbars ff on the adjustable frame B, the pulley J upon theshaft, and the rubber band h, one end of which is connected to saidpulley, and the other end to the adjustable frame B, for taking up thelost motion of the cog-gearing, substantially as herein set forth.

In testimony that I claim the foregoing I have hereunto set my hand this21st day of February, 1874.

'Witnesses: JOEL DAVIS.

I. M. WALLACE, W. G. PRocToR.

